Elevator control system



1933- L. J. KINNARD 1,921,679

ELEVATOR CONTROL SYSTEM 1 I Original Filed Jan. 1 1930 10 Sheets-Sheet l INVENTOR L uf/Mr J Kmxram ATTORNEY 1933- L. J. KINNARD 1,921,679

ELEVATOR CONTROL SYSTEM Original Filed Jan. 11, 1930 10 Sheets-Sheet 2 INVENTOR Fi'g: 2. L u/fiar J K/h/m/"d ATTURNEY 1933- L. J. KINNARD 1,921,679

ELEVATOR CONTROL SYSTEM Original Filed Jan. 1 1930 10 Sheets-Sheet 5 INVENTOR 0777 J Kmnam ATTORNEY A g- 1933' L. J. KINNARD 1,921,679

ELEVATOR CONTROL SYSTEM Original Fild Jan. 1930 10 Sheets-Sheet 4 lNVENTOR A 07% J K/ma/"d I BY ATTORNEY Patented Aug. 8, 1933 warren srarss PATENT oF icE 1,921,679 ELEVATOR. CONTROL sYsTEM Luther J. Kinnard lasadena, (lalifl, assigner te Vlestinghouse. Electric Corporation of Illinois Application .lanuary 11,

Elevator Company, a

1930, Serial No. 420,131

Renewed December 21, 1932 Claims. (Cl. 18'7--29) My invention relates to control systems for electrically operated elevators and more particularly to control systems wherein the elevator cars are operated by the passengers or users 'of the elevator instead of by attendants on the cars.

One object of my invention is to provide a passenger-operated elevator-control system for a plurality of cars wherein the cars will automatically operate in the same manner as they would 10 if handled by experienced car attendants.

Another object of my invention is to provide for so interconnecting the control systems of the carsin a passenger-operated elevator installation that the movement of one car will automatically control the operation of the other cars in such manner as to secure the best results in the operation of the installation as a whole.

A further object of my invention is to provide a passenger-operated control system that will automatically adjust itself, in response to the number of cars in service to operate one car or a plurality of cars, in such manner as to effect the most efficient operation thereof.

It is also an object of my invention to provide a passenger-operated control system that will automatically carry out the following operations.

Although my invention may be applied to an installation embodying a largenumber of cars, it will be considered as applied to a system em-. bodying two cars, each of which is provided with a motor-generator unit, a hoisting motor and a control system therefor.

If traffic is heavy enough to warrant the operation of both cars, the motor generator unit of each car is set in operation. In accordance with my invention the control systems will be thereby automatically so interconnected that the operation of one car will control the operation of the other car and both cars will act as atwo-car collector system. When the cars are operating as a two-car collector system, the normal operation will be such that the cars will be parked at opposite terminal landings when no registered calls are in existence and each car will answer any J iloor calls that may be registered for the direction in which it is in condition to move.

If one of the cars is called from the terminal at which it is parked in response to the registration of a floor call, opposite terminal calls will be automatically registered for each car; that is, of one car starts from its terminal landing, the other car will also start from its terminal. Thus the cars will move to, and park at, opposite terminals. Each car, in moving to its opposite terdirection.

cars will move automatically to the otherterminal, will answer all calls in its direction of movement.

While the cars are moving from one terminal to the other, the direction of movement of the respective cars cannot be reversed until they have arrived at the terminal towards which they are moving. I

If, for any reason, thegate or door of any one of the cars is held open, that car will not move, and the control system of the other car'will be automatically somodified that it will answer all floor calls irrespective of the direction of the calls. However, if the said other car is called from its terminal, it will answer all calls in its direction of movement and complete its trip to the other terminal before it answers any calls in the other For example, if the said other car starts from the bottom terminal in response to one or more floor calls which may be registered in the up direction, and one or more floor calls in the down direction are registered before it starts or before it'has reached the upper terminal, it will start towards the upper terminal but will answer only the up-direction floor calls while it is moving to the upper terminal landing; The down calls which are registered will bemaintained until the car arrives at the upper terminal landing. Upon the arrival of the car at the upper terminal land ing,the down calls will be transferred-to down- 8 direction 'fioor relays for the respective floors from which the calls are registered. The car will then run to, and park at, the lower terminal landing, answering all the down calls in the order of the floors as it makes its down trip.

During the operation of the cars as a two-car collector system, the traffic conditions may be such that both cars may arriveat the same terminal landing at the same time. If the cars are both at the same terminal, and the gates and doors of both cars'are held open, the cars will stay at this terminal landing until thegate and door of one of them are closed. In this case, the car first to have its gateand door closed will move automatically to the other terminal landing, at which it will park so long as no calls are registered, provided the gate or door of the other car is still held open. The control system, how ever, is so arranged-that the moving car will answer all calls in its direction'of travel as it goes i to the other terminal.

If the gates and doors of both cars are closed, when both cars are parked at the same terminal landing with norfloor calls registered, one of the minal landing and will park at that landing while the other car will stay where it is. Each car will now be disposed to answer all floor calls in the direction in which it is conditioned to move.

As stated above, if both cars are parked at the same terminal landing with their gates and doors open, and the gate and door of one car are closed, the closed car will be dispatched towards the other terminal and will answer any calls that are registered in its direction of movement. If, after the first closed car has started, the gate and the door of the second car closed, and a car push button thereinis operated to set up a call for a floor intermediate the terminal landings, then the second car will also start towards the terminal landing to which the othercar is moving.

After the second car starts to follow the first car, the control system will be so modifiedthat.

the first car will answer only those calls which were registered beforethe second car started, and the second car will answer all the calls registered after it star-ts. Therefore, the car last to start will be caused to stopat every floor from which a call in the direction of, movement or" the caris registered subsequent to its starting.

Accordingly, "thecar first to start willarrive at its terminal landing ahead of the car last to start; Immediately upon the arrival of they first car at the terminal landing, a floor call for the other or opposite terminal landing will 'be registeredautornatically to cause it to be dispatched to said opposite terminal. Therefore, the control systems of the :cars will tend to keep them moving in opposite directions and to cause them to be, parked at opposite terminals when they are not answering registered calls.

If traffic conditions are light and it is not" necessary to employ both cars, the motor-generator unit of one car be shut down, so that the other car may act as a single-car-collector system. In case, the other car will be disposed to answerall floor calls. The control system, however, is so arranged that'the active car will answer all calls in a given direction in the order or" the floors and not in the order of the calls, before any floor calls in the opposite direction are answered, provided the opposite-direction calls are registered last. 7

If a passenger standing at a floor landing desires to call a car to that fioor, it is only necessary for him to operate a pushrbutton corresponding to the direction in which he desires to go; The car which is in condition to answer this call will move to stop. at and remain at, that floor for a length of time sufilcient to permit the passenger to open the gate and door and enter the car. After the passenger enters the car, and the gate and door are reclosed, if he presses a push-button in the carcorresponding to the particular floor to which he desires to go, the car will move to that floor. When the car arrives at that floor it will stop so that the passenger mayleavc the car. After the passenger leaves the car and the gate and door close, the

car will continue on its way, stoppingat each taken in conjunction with the accompanying drawings, in which: i

Figures 1, 2, 3. and 4 collectively constitute a full-line diagrammatic representation of a pas-' stinger-operated elevator-control system embodying my invention;

Figs. 5, 6, "7, 8, 9 and 10 collectively constitute a straight-line diagram or thecircuits and apparatus included in l, 2, 3 and i; and

Fig. 11 is a schematic illustration of a direction-prefecnce relayembodied in the control system shown in l to 10, inclusive.

For the'sake of simplicity, so that the various circuits may be traced easily, my invention will he "described in connection with the straightline diagram embodied in Figs. 5 to 10, inclusive, of the drawings, and, when possible, the reference numerals that are applied to the straight-line drawings will be applied also to the corresponding parts and circuits in the full-line drawings to permit ready reference to either set of drawings.

In the drawings, I have illustrated an elevator system embodying two cars A and B that are disposed to operate past-a plurality of floors. As shown, they are adapted to serve an upper terminal, a lower terminal and two intermediate floors. i v

Inasmuch as the cars A and B and the means for operating them are similar, only car A will be described in detail and car B, with its accessories, will be given similar reference characters with the prefix B. c

As an aid in understanding the system, the following list of switches, rela and other parts for car A is given:

lVl hoisting motor. n

G generator to supply energy to hoisting motor.

9. Separately excited field winding-for gener ator whereby operation of generator is controlled. 1 v

10 deinagnetizing field w nding for generator. Dlvlinotorfor driving ge v.erator. L1 and L2 conductor for supplying energy Iron-i outside source to operate driving. motor BM.

EX exciter driven by driving motor El /l for supplying energy to field windings of hoisting motor and generator and also to control circuits ES high-speed relay also controlled by relays 33 and 34. I

37, 39 up-direction floor relays for energizing Lip-control relay 411, as down-direction floor relays for energizing down-control relay 34. f'he f'loor relays also energize contact segments on a floor selector to stop the car at the correct floor.

45 46 up-direction push buttons in car for e:.1ergizing up floor relays. a

43?, 49 down-direction push buttons in carfor energizing down floor 51, up corridor relays for energizing up floor relays.

'54, 55, 58 tip-direction push buttons at landings for energizing up corridor relays.

'7, 58, 59 down corridor relays for energizing door floor relays.

61, 62, 63 down-direction push buttons at landings for energizing down corridor relays.

64 floor selector for connecting circuits according to travel of car.

'71 tip-direction preference relay for stopping, retaining direction and restarting car on up trip.

72 down-direction preference relay for stopping, retaining direction and restarting car on down trip.

79 inductor relay on car for stopping car.

121 up call relay to insure car goes to "up terminal.

101 down call relay to insure car goes to down terminal.

171 top floor terminal relay to park car at upper terminal.

102 bottom floor relay to park car at lower terminal.

304 and E384 dual operating relays for interconnecting control circuits with both cars in operation.

380 and B380 relays for conecting certain circuits with only one car in operation.

81 starting switch in car A for energizing starting relay 82.

82 starting relay for setting motor-generator set into operation.

The car A is suitably suspended upon a cable 1 that passes over a hoisting drum 2 to a suitable counterweight W. The hoisting drum 2 is directly coupled to the armature 5 of a hoisting motor M, the field winding 6 of which is connected, for constant-voltage energization, to a source of power designated as the supply conductors 13 and 14.

A variable-voltage system of control is provided for operating the hoisting motor M, wherein the armature 5 of the hoisting motor is connected in loop circuit with the armature 7 of a generator G. The generator is provided with a cumulative series field winding 8 and a separately excited field winding 9. A demagnetizing field winding 10 is provided for reducing the residual magnetism of the generator to approximately zero value when the separately-excited field winding 9 is deenergized.

The armature '7 of the generator G is directly coupled to, and is driven by, a driving motor DM illustrated as being of the shunt-wound type having its armature DM and its field winding DMF connected in shunt relation to a source of supply designated by the supply conductors L1 and L2.

An exciter EX is provided for supplying power to the supply conductors 13 and 1 1 for the field winding 6 of the hoisting motor, the separatelyexcited field winding 9 of the generator G and the cl'cuits of the control system. The exciter EX is directly coupled to, and is driven by, the driving motor DM through a shaft 4.

The direction and speed of the hoisting motor M may be suitably controlled by controlling the direction and value of the excitation current that is supplied to the separately excited field winding 9 of the generator G.

The direction of the excitation current for the field winding 9 may be suitably controlled by means of an up-direction switch 11 and a downdirection switch 12, while the value of the current supplied to the field winding may be controlled by means of a high-speed relay HS.

For instance, if the rip-direction switch .11 is energized, it disconnectsthe demagnetizing field winding 10, supplies energy from the supply con-' ductors 13 and l ito the separately excited field winding 9 of the generator G, and connects the hoisting motor M to the generator G to cause the car A to travel upwardly.

The closing of the contact members a andb on the upire'ction switch 11 completes a power circuit for the field winding 9 that extends from the power supply conductor 13, through conductor l5, junction point 16, contact members a of the switch 11, conductor 17, the field winding 9, conductor 18, contact members b of the switch 11, conductor 19, and an accelerating resistor to the power-supply conductor 14:.

The closing of the contact members c on the switch 11, completes a power circuit for the motor M that extends from the armature 7 of the generator G through conductor 21, contact members 0 of the switch 11, conductor 22, the armature and the shunt field winding 6, connected in parallelcircuit relation, andthe series field winding 8 back to the armature '7 of the generator.

When the up-direction switch 11 is deenergized for the purpose of stopping the car, the hoistiag motor M is disconnected from the generator G; the separately excited field winding 9 is disconnected from the supply conductors 13 and 14; and the demagnetizing field winding 10 is connected across the armature 7 of the generator G.

The circuit for the demagnetizing field winding 10 extends from the armature '7 of the generator G, through the series field winding 8, conductor 24, demagnetizing field winding 19, contact memher (i of the up direction switch 11, conductor '25, contact members d of the down direction switch 12 and conductor 26, back to the armature '7 of the generator.

If the down-direction switch 12 is closed, the hoisting motor M is connected to the enerator G; the separately excited field winding 9, is reversed and connected to the power-supply conductors 13 and 1 1; and the deinagnetizing field winding 10 is disconnected from the armature 7 of the generator. Since the field winding 9 is reversed, the current in the winding fiows in the opposite direction to that in which it flows when the up-direction switch 11 closed. Accordingly, the voltage developed by the generator is reversed, and the motor is caused to drive the car downwardly, when the down direction switch 12 is closed.

The energizing circuit for :the separatelyexcited field winding 9, when reversed, extends from supply conductor 13, through conductor 15, contact members 5 of the down-direction swl'tcl'i' l2, conductor 18, field winding 9, conductor 17, contact members a of the switch 12 and the accelerating resistor 20, to the: supply conductor 14.

In order to stop the elevator car A when the hoisting motor M is disconnected-from the generator G, a brake 27 is provided and disposed for operation upon a brake drum 28 that is mounted on the drive shaft 3; As shown, the brake27 is applied by a spring 30 when the motor is disconnected from its source of power and is released by a solenoid 29 when power is applied to the motor. The solenoid 29 is controlled by a brake relay 133 the coil of which is included in the 'circuit to the up and down-direction switches 11 and 12.

In order that the up and down-direction switches 11 and '12 may be closed when it is desired to start the'car, up and down-direction relays 31 and 32, respectively; are provided. These relays, when closed, operate to'establish energizing circuits for the respective actuating coils of the direction switches 11 and 12.

An .up-control relay 33 and a down-control relay 3d are provided for energizing the direction relays 31 and 32 in starting the car and forenergizing a high-speed relay ES to cause the car to travel at high speed after it is started. The circuit for the high-speed relay HS, when energized, extends from the supply conductor 13, through conductor 121', the coil of relay HS, conductor 122, the contact members a of either the relay 33 or the relay 34 and conductor 125, to supply conductor l4.

The car A has associated with it a plurality of up-direction floor relays 37, 38 and 39 for energizing the up-control relay 33, and a plurality of down-direction floor relays 41, 42 and 43 for energizing the down-control relay 34..

When afioor relay is energized to close a control relay to run the car to a floor, it also supplies energy to one of a pair of contact segments on a floor selector 64, which contact segments are disposed to be closed by the arrival of the car at the corresponding floor to thereby energize a stopping relay 71 or '72, to effect the stopping of. the car at that floor, as will be more fully explained later.

The floor relays are, in turn, energized by means of passenger-operated push buttons that are located in the car and at the floor landings.

Therefore, when a floor relay is energized by the pressing of a push button, it causes a car to move to the floor corresponding to the pressed push button and then stops it at that floor.

It will be noted that the'normally open contact members I) of the floor relay 39 are connected to the armature of that relay by a springthat per- 7 mits the armature to continue its upward movebers h after the armature has moved upwardly a short distance. 7

that, when the relay 39 is energized by a circuit This construction is provided so extending through its normally closed contact "members It, as is sometimes necessary, its normally open contact members 5 will close and complete a self-holdirr circuit for itself before the'contact members it open.

The floor relays 41, B39 and 1341 are constructed with their contact members 1) audit mounted the same as on the relay 39.

The push buttons disposed in the car A to be operated by the passengers in order to move the car to, and stop it at; any selected floor are i designated as e i,' -5 and 46 for the up direction and 47, 4:8 and l9 for the down direction. The car push buttons are connected in the circuits for the coils of the floor relays corresponding to the car A.

The push buttons disposed at the corridor landings for operation by waiting passengers to register calls for bringing the cars to them are designated as 54, 55 and 56 for the up direction and 61, 62 and 63 for the down direction.

Onlyone'set of floor buttons is provided. In order toavoid the necessity of having a set or floor push buttons for each car, they are connected to energize corresponding corridor relays that,

in turn, selectively energize the floor relays of the car that should next reach-that floor in the corresponding direction. .The up floor push buttons 54, 55 and 56 are connected for selectively energizing up corridor relays 51, 52 and 53 while the down push buttons 61, 62 and 63 are connected for selectively energizing downcorridor relays 57, 58

and 59.

When both cars are in service, the up corridor relays 51, 52 and 53, when energized, will be connected either through contact members 65, 66 and 67 on the floor selector 64 to the up floor relays for car A or through contact members B65, B66 and B67 on the floor selector B6 z to the up floor relays f or car B, depending upon the position and the direction of travel of the cars.

Similarly, the down corridor relays 57, 58 and 59, when energized, will be connected, through contact members 68, 69 and 70 on the floor selector 64, to the down floor relays for car A or, through the contact members 1368, B69 and B70 on the floor selector B64, to the down floor relays for car B, depending upon the position and direction or" operation of the cars.

The floor selector 6% for connecting certain circuits to the stopping relays, the floor relays, etc., of car A in accordance with the movement of the car may be located at any suitable point, for example, in the penthouse of the elevator shaft. As shown, the selector is provided with two sets of contact segments that are disposed to be closed by brushes 35 and 35a and a plurality of switches that are disposed to be operated by a pair of pins 351) and 350. The brushes and pins are seated upon a movable arm MA that is operated in accordance with the movements of the car A by means of a screw S which is driven by some part of the operating mechanism of the car.

Thecontact segments '76, 7'7 and '78 under the brush 35 may he energized by the down floor relays so that they will effect the stopping of the car on a down trip as they are closed by the brush 35, while the contact segments '73, 74 and 75 under the brush 35a may be energized by the up floor relays to stop the car on an up trip, as they are closed by the brush 35a.

The contact segments 76, 7'7 and '78, as well as the segments '73, 74 and '75, are disposed in such position on the floor selector with reference to the floorlandings as to provide slow-down zones Within which the car may be decelerated so that it maybe stopped exactly level with the floors.

The contact segments 153 are disposed to be engaged by the brush 35 to energize a top terminal landing relay 147 when the car A is at the upper terminal. Similarly, the contact members 160 are disposed to energize a bottom terminal landing relay 159 when the car A is at the lower terminal. The landing relays 147 and 159 prepare certain circuits to cause the cars to operate in a certain order under certain conditions.

The pin 35b is disposed to consecutively engage small projections on the rear ends of the switches under it and thereby open the contact members jections on the switches under it to consecutively open contact members 296 and 290 to prevent the operation of certain floor relays under certain conditions and to close contact members 67, 66 and 65 to prepare the floor relays 39, 38 and 37 I a l '41.! The pm 35c 18 disposed to engage small pro- J for energization as the car travels downwardly; Obviously, as the car travels upwardly, the position of the switches will be reversed.

It should be noted that the switches under the pins 351) and 350 are placed upon the floor selector in such position'that they will be moved to open position as the car comes into a floor and, as the car leaves the floor, they will be moved to close the opposite contact members.

In stopping the car at a landing, it is desirable to first reinsert the resistor 20 in the generator field to slow down the car and then, as the car slows down to stop at a landing, to cut off the power and apply the brake to bring it to a standstill exactly level with the landing. In the present system, the resistor 20 is reinserted in the generator field when the control relays 33 and 34 are deenergized as the car enters the slow-down zone. It should be recalled that the direction relays and the direction switches will not be deenergized to cut oil the power as soon as the control relays 33 and 34 are deenergized because the direction relay circuit through the control relays has been paralleled by a holding circuit through the contact members of the inductor relay 79. Therefore, after thecontrol relays are deenergized, the direction relays remain energized until the contact members of the inductor relay 79 are opened.

In order that the up-control relay 33 may be deenergized to initiate sloW down of the car A asit enters slow-down zone for any floor for which a call has been registered, the stopping and up-direction preference relay '71 is provided.

Similarly, the stopping and down-direction preference relay '72 is provided for deenergizing the doWn-controlrelay 34 as the car descends to any floor from which a call is registered.

The direction-preference relay 71 is energized as the car Aenters the slow-down zone of each of the difierent floors for which a call is registered, by the brush 35a moving over and closing one of the energized contact members 73, 74 and '75 on the floor selector 64. These contact members are so arranged that a momentary circuit is established for the relay '71 when the. car enters the slow-down zone for any floor, provided the up floor relay for that floor has been energized to supply current to its corresponding contact segment. Upon closing, the relay '11 establishes its own holding circuit.

In like manner, the down-direction preference relay 72 will be energized by the brush 35 engaging and closing one of the energized contact seg-' for the next operation. When all the calls in theup direction have been answered, the up-direction preference relay 71 cannot be reenergized unless another-up call is registered before the car reverses. This is also true of the down-directionpreference relay 72, for the down-direction calls.

In order that the car A, after being decelerated, may be stopped on a level with any iioor for which a call is registeredan inductor landing relay 79 is provided. This relay is disposed to be energized whenever the one or the other of the directionpre:terence relays '71 and 72 is energized. As the car slows down to a position approximate:

ly level with theiioor, the inductor relay 79 passes inductor plate and is thereby operated to deenergizeeither the up-direction relay 31 or the down-direction relay 32, depending upon whether the car is moving in the up or in the clown direction. when. the direction relays 31 and 32 are decnergized, they open the direction switches 11 and 12 to cut off the power and, at the same time, apply the brake to stop the car exactly level with the landing.

In. order that, when both cars A and B are in service and one of them is started in either direction, it shall continue to travel in that direction each stop is to take on or let off passengers until it arrives at the opposite terminal, I have provided the car A. with an up call relay 121 and'a down callrelay 101 and car B with an up call relay B121 and a down call relay 3101. As

previously stated, the direction-preference relays condition the cars to restart after a call has been answered as long as further calls exist, but the call relays insure that the cars Will keep on going until they land at the terminals in the direction in which they start even though no further registered calls are in existence.

The car A is provided with a top floor terminal relay 171 and a bottom floor relay 102. Car B is provided with a similar pair of relays B171 and E102. When both cars are in service, these floor-terminal. relays cause them to park at opposite terminals and, at the same time, control the energization of transfer conductors 155 and 167 for car A and conductors B155 and 13167 for car B in such manner that the cars, when moving in one direction, will not answer calls in the other direction. For instance, if car A receives a down call while it is at the top floor, it will start down to the bottom floor and car 13 will start up to the top floor. While car A'is going down, it will answer all down calls but no up calls, while car 3 will answer all up calls but no down calls.

Dual operating relays, 304 for car A and B304 for car B, are provided to interconnect certain control circuits of the cars when both cars are in operation so that the cars will follow certain routines. When only one car is in service, the dual operating relay of the other car is not energized and it, therefore, preventsthe completion of certain circuits that would cause the-operating car, after starting in one direction, to make a trip to the terminal that direction.

- Associated with, and energized by, the relays 30 i and E304 are relays 380 and B380 for connecting certain circuits when only one car is in operation. It will be noted that the relays 380 and E380 are provided with dash pots that prevent their normally clos d contact members g and from openin quickly when the relays are energized. The use of the dash pots permits the formation of certain holding circuits between the energization ofthe relays 380 and E380, and the opening of their contact members g and 7.

As a matter of safety, it is desirable to prevent either one of the control relays 33"and 34 from being energized. to start the car A until the gate and the doors are closed. Therefore, a gate and door relay 36 is provided to hold open the ciredits of the control 'relays'33 34 until the gate and doors are closed. Gate and door interlocks are provided to energize the relay 36 in the usual manner when .the'gate and doors are 'ductors BL2.

. arranged that, when the systems are operating as a two-car collector control system, the control'system of one car functions to govern the control system of the other car. Furthermore, these control systems are so arranged that either of the cars may be operated independently as a single car-collector system.

The operation of the cars as a two-car-collector-control system will be described first. In describing the various steps of operation, it will be assumed that the car'A is parked at the upper terminal landing and that car B is parked at the lower terminal landing. The first step in the operation of the system requires that the motor-generator units of both cars be placed in operation. v v

To start the motor-generator unit for car A, a starting switch 81 disposed in that car is actuated to its closed position. The closing of the starting switch 81 completes a circuit for energizing the actuating coil of a starting relay 82 to connect the driving motor DM to the supply conductors L1 and L2, which circuit extends from one ;of the power-supply conductors Ll, through the contact members of the starting switch 81, conductor 84 and the actuating coil of the starting relay 82, to the supply conductor L2.

Energization of the starting relay 82 completes a circuit for the driving motor DM that extends from the supply conductorLl, through the armature and the shunt field windings of the motor and the contact members of the starting relay, to the supply conductor L2.

Under the assumed conditions, when the A motor-generator unit for car A starts, the exciter supplies power to the supply conductors 18 and 14, and a circuit-connecting relay 84 is energized to provide a certain set up of the control circuits of car A that will enable that car to function correctly. The circuit for energizing the relay 84 extends from conductor 13, to the actuating coil of the relay 84, through the conductor 14. When the relay 84 is energized, its contact members a, b, c, d, e and k are closed-to ener-, gize the control circuit for car A. y

In order to start the motor-generator unit forv car B, a starting switch B81 disposed in car B is closed to complete a circuit for energizing a; starting relay B82, which circuit extends from a supply conductor BLl, through the contact members of the starting switch B81'and the actuating coil'of the starting relay B82, to the powersupply conductor BT42.

vThe closing of the starting relay B82 'completes a circuit for the'driving motor BDM to operate the motorgenerator unit, which circuit extends from the supply conductors BLl through the contact members of the starting relay 1382 through the armature and the shunt field Windings in parallel and thence,t-o the supply con- When the motor-generator unit for the car B starts, the exciter BEX supplies current for the supply conductors B13 and B14 and, at the same time, automatically energizes a circuit-connecting relay B84. The energizing circuit forthe coil of 'therelay B84 extends from control-circuit conductor 1313, through the actuating coil oil the relay 384, to a control-circuit conductor B 4.

When the relay B84 is energized, its con-. tact members a, b, c, c'andk are closed toicon nect the control circuits of car B in such manner that the car may be operated under the assumed conditions. 'With "both cars in service, they, are so interconnected by the relays 84 and B84 that their control circuits are supplied with power from the exciter clear A only, because the normally closed contact members I and g of the car A relay 84 are open.

After the motor-generator set for car 13 is started, the door and'gate for car B are closed.

close its contact members a, b and c to permit operation of the car A, which circuit extends from supply conductor 3, through the door and gate interlocks and the coil of relay 36, to supply conductor 14. i

Stated briefly, the pressing of the button 47 energizes the floor relay 41, which, in turn, causes the energization of the downcontrol relay 34, the down-direction relay and the down-directionswitch 12 to complete circuits for. sup-' plying current to the generator field and for connecting the hoisting motor to the generator to start the car downwardly. The energized floor relay 41 also closes a circuit to supply current to one of the contact segments '78 on the floor selector for operating relays to stop the car when it arrives at the first floor.

Stated in detail, the pressing of the push button 47, by reason or" the position of the cars,-

completes a circuit for energizing the actuating coil of the down floor relay 41 of car A, which circuit extends from a supply conductor 13, through the contact members b of the relay 84, control circuit conductor 87, junction point 88, conductor 89., contact'members a of therelay 84, conductor 90, junction point 91, conductors 92 and 93, the contact members of the first-floor car push-button 4'7, conductors 94, 95 and 96, contact members 68 of the floor selector 64, conductor 97, the actuating coil of the relay 41, control'circuit conductors 98 and 99, control-circuit conductor B99 and contact members c of the relay 34, to control-circuit supply-conductor The closing of the contact members 12 on the floor relay- 41 completes a self-holding circuit for that relay extending from control-circuit conductor 92, through conductor 103, contact members b of the relay 41, conductors 104, 95 and 96, the contact members 68 of the floor selector, conductor 97, the coil of the relay 41, and conductor 98, to the control circuit conductor 99, which is energized. The relay 41 will remain energized until the pin 35b on the floor selector 64 opens the contact members 68 when the car reaches the first floor.

The closing of thecontact members I) on the clown floor relay 41 also energizes one of the contact members '78 on the floor selector. 64 so that when the car A enters the slow-down zone for the bottom floor and thereby causes the brush 35 toclose the contact members 78, a circuit will be completed for energizing the down preference re- -lay 72 to stop the car atthe bottom floor.

The closing 01' the contact members'a of the floor relay 41 completes an energizing circuit for the down call relay 101 to cause the car A to make a trip to the lower terminal, which circuit extends from the energized conductor 108, through conductor 116, normally closed contact members h of an up call relay 121, conductor 117, the coil of relay 101, conductor 118, normally closed contact members it of the relay 31 and conductors 119 and 120, to the control circuit conductor 99.

The opening of the contact members It on the energized down call relay 101 prevents the energization of the up call relay 121 during the down trip of the car A.

It should be noted that down call relay 101 for car A will be energized whenever any one of the down floor relays 43, 42 or 41 is energized, because the contact members a of each of the down floor relays for car A are connected to the common conductor 108 which supplies energy to the coil of the relay 101.

The down call relay 101, if energized by either of the down floor relays 42 or 43, will close its contact members a to complete a circuit for energizing the down floor relay 41 for the bottom floor to thereby cause the car A to go to the bottom floor provided it starts on a down trip when car (Bit B is also in service. Thus, it will be seen that the down floor relay 41 for the lower terminal may be energized either by the down car push. button 47 or by the down call relay 101. In the present instance, the floor relay 41 has been energized by the push button 47 instead of by the down call relay 101 and, therefore, the present energization of relay 101 serves no purpose except to prevent the energization of the up call relay 121 for car A while it is making a down trip.

The closing of the contact members a on the down floor relay 41 also completes an energizing circuit for the down control relay 34 which extends from the energized conductor 96, through conductor 105, the contact members a of the relay 41, down-direction floor-relay circuit conductor 108, conductor 100, normally closed contact members g of the up-direction relay 31, conductor 110, normally closed contact members y of the up-direction-preference relay 71, conductor '111, normally closed contact members a of the direction-preference relay 72, conductor 112, the actuating coil of the down control relay 34, conductor 113, normally closed contact members 9 of the up-direction control relay 33, conductor 114, normally closed contact members 1 of theup-direction relay 31 and conductor 115, to the control circuit conductor 99, which is energized.

It should be noted here that the down floor relay circuit conductor 108 is common to all the down floor relays of car A and that it is in an energized condition when any one or all of the down floor relays are energized, so that it will in turn, control or supply current to the down call relay 101 and the down control relay 34 to move the car downwardly whenever any down floor relay for car A is energized.

The closing of the contact members 0 on the energized control relay 34 completes an energizing circuit for the dcwn-direction relay 32 which extends from the car-button-control-circuit conductor 92, through conductor 127, contact members c of the control relay 34, conductor 123, junction point 129, conductor 130, the actuating coil of the down-direction relay 32, conductor 131, contact members 0 of the gate relay 36, conductors 132 and 114, the normally closed contact members f of the lip-direction relay 31 and conductor 115, to the car A control-circuit conductor 99.

The closing of the contact membersv a on the energized down-direction relay 32 completes a circuit for energizing the down-direction switch 12 and the brake-releasing relay 133 for starting the car, which circuit extends from supply conductor 13, through conductor. 201, the contact members a of down-direction relay 32, the coil of down-direction switch 12, conductor 205, the coil of brake relay 133 and conductor 206, to supply conductor 14.

The energization of thedowrvdirection switch 12 and the brake relay 133 causes them to supply the hoisting motor with power and thus release the brake 27 from the brake drum 28, as previously described, thereby starting the car down- Wardly. U

The closing of the contact members 0 on the energized down-direction relay 32 also completes a self-holding circuit for itself which circuit is in parallel with the contact members a of the floor relay 34 and extends from the car-buttoncontrol-circuit conductor 92 through conductor 134, normally closed contact members 1;. of the inductor landing relay 79, conductors 135 and 136, the contact members 0 of the relay 32 and conductor 137, to the conductor 128. The provision of: the parallel holding circuit prevents the direction relay 32 from being deenergized when'the contact members 0 onthe control relay 34 are opened, until the circuit through the contact members I) of relay 79 is opened.

Therefore, when the car enters the slow down zone for a floor at which a stop is to be made, the control relay 34 will be deenergi'zed by the energization of the down preference relay 72 to open one or" the parallel circuits to the coil of relay 32 and, atthe same time, to insert the resistor 20 in the circuit of the generator field winding 9 for slowing down the car. When the car slows down to stop at the landing, the inductor fioor relay 79 will open its contact memhers I) to break the self-holding circuit of the direction relay 32 and thus cause the power to be cut off the hoistingimotor and the brake to be applied, thereby bringing the car to a standstill at the landing.

Returning to the energization of the floor relay 41, the closing of its contact members 0 completes an energizing circuit for the bottom terminal relay 102 of car A to cause car B to go to the top landing and to cause car A to answer only down calls and car 13 only up calls, which circuit extends from the contact members a of the relay 84 through conductor 138, junction point conductor 150, contact members 0 of the first floor relay 41, conductor 151, the actuating coil of the relay 102 and conductor 152 to the controlcircuit conductor 99. The relay 147 is energized when the car A is parked at the top-floor terminal because normally open contact members 153 of the floor selector are closed.

The closing of the contact membersa on the lower terminal relay 102 energizes a down transfer conductor 155 so that any 'calls registered on the down corridor push buttons 61, 62 and 63 will be transferred to the car A floor relays 41,

42 and 43 bythe corridor relays 57,58 and 59 to cause car A to'make the corresponding down stops.

CPI

. corridor calls that may be registered from the corridors of the several floors when it is moving from the lower terminal to the upper terminal.

The closing of the contact members I) on the lower terminal relayv 102 automatically completes an energizing circuit for the floor relay B39 to cause car B to move from the bottom terminal to the top terminal, which circuit extends from the control circuit conductor 87, through a conductor 156,'the contact members b of the relay B84, conductors B138, B140 and 131%, contact members a of the gate relay B36, c0nductorB143, junction B1 14, conductor B157, normally closed contact members w of the down-direction preference relay B72, conductor B158, contact members a of the down floor terminal relay B159, v(which relay is energized when lower terminal landing contact members B160 of the floor selector B64 are closed,)

. conductors B161 and E163, normally closed contact members 1 of the relay 171 of car A, conductor B165, junction point B166, the up-direction corridor relay transfer conductor-B167, conductor B168, contact members I) of the, relay 102 of car A, conductors B169, B367 and B174, contact members B67 of the floor selector B64, conductor B175, the actuating coil of the relay B39 and conductor B176, to the control-circuit conductor B99 which is energized.

The closing of the contact members I) on the energized up floor relay B39 completes a holding circuit for that relay extending from conductor B92,through conductor B172, contact members 7.) of the relay B39,conductors B173 and B174, contact members B67 of the floor selector, conductor B175, the actuating coil of the relay B39 and conductor B176, to the energized conductor B99. The relay B39 will now stay energized until the contact members B67 on the floor selector B64 are opened when the car B passes the slow down zone for thetop terminal floor. 1 e

The closing of the contact members I) on the up floor relay B39 also energizes one of the contact members B on the floor selector B64 so that, when the car B enters the slow down zone for the top floor and thereby causes the brush 335a .to close the contact members 76 on the floor selector B64, a circuit will be completed for energizing the down preference relay B72 to stop the car at the top floor.

The closing of the contact members, a on the energized up floor relay B39 completes a circuit for energizing the up call relay B121, which circuit extends from the conductor B174, through conductor B177, the contact members a of relay B39, up floor-relay conductor B178, conductor 186, normally closed contact members h of the down call relay B101, conductor B187, the actuating coil of the up call relay B121, conductor B188, normally closed contact members h of the relay B32 and conductors B119 and 1312 0, to the energized conductor B99. I

The opening of the contact members it on the up call relay B121 prevents the down ,call relay B101 from being energized while any up floor relays for car B are energized. Therefore, inasmuch as the floor relay 1339 for the top floor is energized, the car B will make a complete trip to the top'floor if it starts in that direction.

The closing of the contact members a on the up callrelay B121 does not, in this case, energize relay B39 because that relay is already energized.

The closing of the contact members cof the floor relay B39 completes a circuit for energizing the topfioor terminal relay B171 to cause car B to answer all up calls, which circuit extends from the junction point B1 14 (that is energized when the gate and door are closed) through conductor B157, normally closed contact members w of the relay B72, conductor B153, contact members a of the relay B159, conductor B161, junction point B162, conductor B191, contact members 0 of the iioor relay B39, conductor B192, the actuating coil of the relay B171 and conductor B193, to the energized conductor B99.

The opening of the contact members f on the terminal relay B171 deenergizes the up transfer conductor 167 and prevents the car A from re-- ceiving up corridor calls while it is going down.

The closing'of the contact members a on the terminal relay B171 energizes the up transfer conductor B167 to cause the car B to answer all up corridor calls as it makes its up trip.

As previously described, the opening of the contact members 1 and the closing of the contact members a on the relay 152 deenergized the down transfer conductor for car B and energized the down transfer conductor for car A. Therefore,

when the car B is parked at the lower terminal landing and the car A at the upper terminal landing with their gates and doors closed, all up calls will be answered by the car B and all down calls will be answered by car A.

The closing of tie contact members a on the floor relay B39 also completes anenergizing circuit for the up-direction control relay B33 to cause the car B to move upwardly, which circuit extends from the conductor B17 1, through conductor B177, the contact members a of relay B39, conductors B173 and B179, normally closed contact members 9 of the relay B32, conductor B180,

normally closed contact members a: of the up-cli rection preference relay B71, conductor B181, normally closed contact members 11 of therelay B7 2, conductor B182, the actuating coil or" the up control relay B33, conductor B183, normally closed contact members 9 of the down control relay B3 1, conductor B18 1, normally closed contact members 7 of the down direction relay B32 and conductor B185, to the conductor B99.

The closing of the contact'rnembers a on the up-direction control relay B33 completes an energizing circuit for the high-speed relay BHS for causing the resistor B20 to be short-circuited so that generator will develop, full voltage when the up-direction switch B11 is closed.

Theclosing of the contact members 0 on the control relay B33 completes a circuit for energizing the up-direction relay B31 which circuit extends from the car push-button control-circuit conductor B92, through. conductor B194, the contact member 0 of the relay B33, conductors B195 and B196, the actuating coil of the up direction relay B31, the contact members I) of the gate relay B36, conductors B197 and B184, the normally closed contact members f of the down-diconductor B92, through conductor B134, the contact members I) of the inductor landing relay B79, conductor B135, the contact members 0 of the up direction relay B31 and conductor B200,

to the conductor B195. Therefore, when the updirection high-speed relay B33 is deenergized to initiate slow-down of the car as it approaches a floor, the relay 331 will remain energized until the inductor landing relay B73 operates to open its contact members 72 and stop the car.

The closing of the contact members a on the rip-direction relay completes a circuit for energizing the rip-direction switch B11 and the actuating coil of the bral e-releasing relay B133, which circuit extends from the control-circuit conductor B13, through conductors B201 B202, contact members a of the lip-direction relay B31, conductor B203, the actuating coil of the up-direction switch B11, conductors B234 and E205, the coil of the relay B153 and conductor B206, to the control-circuit conductor The energization of the rip-direction switch B11 causes the motor BG to drive the car upwardly, as previously described.

The car A is now moving towards the firstfloor landing at high speed, and the car B is moving towards the top-floor landing at high speed.

Assuming that, at the moment, the cars A and B have started toward their respective terminal landings or shortly thereafter, a waiting passenger registers a down call from the corridor of the third floor, then the down-directioh relay 43 of car A will be energized to stop car A at the third floor.

The pressing of the down push button 63 at the third-floor corridor compl tes a circuit for energizing the down corridor relay 59,1V111Ch circuit extends from the control-circuit conductor 87, through conductor 26?, the contact members of the push-button switch 53, the conductor 208, the actuating coil of the third-floor corridor relay 59, conductor 209, the normally closed contact members 7 of the down floor relay 43, conductor 210, the normally closed contact members 1 of the down floor relay B43 and conductors 211 and 348, to the control-circuit conductor B99.

The closing of the contact members a on the corridor relay 59 completes a self-holding circuit for that relay extending from th control-circuit conductor 87, through conductor 212, contact members 2 of the relay 34 of car A, conductor 213, the contact members a of the relay B84, conductor 214, junction point 215, conductors 216 and 217 and the contact members a of the down corridor relay to the conductor 203.

The closing of the contact members b on the corridor 59 completes a circuit for energizing the floor relay 43 for car A, Whichcircuit extends from the junction point 334 of the transfer conductor 155 (which is energized, because the contact members a of the relay 102 are closed), through conductor 218, the contact members I) of the corridor relay 59, conductors 219 and 225, the contact members of the floor selector 64, conductor 221, the coil of the floorrelay 3 and conductor 222, to the control-circuit conductor 99.

It is to be noted that the corridor relay 59 is also provided with contact members c for clos ing a circuit through the transfer conductor 3155 for energizing the third-floor down relay B43. But, since the down transfer conductor B155 is deenergized, no circuit can be completed now for energizing the down floor relays of 1 car 13.

The floor relay 43, of car A, upon being energized, closes its contact members 5 to complete a self -holding circuit for itself that extends from the car-button-control-circuit conductor 92, through conductor 223, thecontact members '5 of the floor relay 43 and conductor 224, to the conductor 219.

The opening of the contact members f on the downrloor relay 43 deenergizes and restores the down corridor relay 59.

Also, upon the closure of the floor relay 43, a circuit is established for the down-directioni'loor-relay-circuit conductor 108 that extends from. conductor 220, through conductor 225, the contact members a of the relay 43 and conductor 226, to the floor-relay circuit conductor 1G3. It to be noted that the conductor 103 is energized when any one of the down fioorrelays for car A is energized, for the purpose of preparing circuits to be completed later in the operation of the down preference relay 72. p

The closing of the contact members I) on the down floor relay 43 also energizes one of the contact members 76 on the floor selector 64 so that, when the car A enters the slow-down zone for the third iioor and thereby causes the brush 35 to close the contact members 76 on the floor selector, a circuit will be completed for energizing the down preference relay '72 to stop the car at the third floor.

As the car A enters the slow-down zone for the third floor, the brush 35 on the floor selector engages and closes the floor-selector contact members 75, thereby completing a circuit for energizing the down-direction preference relay 72 to cause the car to slow down and stop, which circuit extends from the energized conductor 921, through conductor 227, normally open contact members 76 of the floor selector 64, conductor conductor 229, contact members k of the down high-speed relay 34, conductor 230, junction point conductor 232, the actuating coil of the relay 72, conductor 233, conductor 113, normally closed contact member g of the up control relay 33, conductor 114, normally closed contact members 1 of the up-direction relay 31 and conductor 115, to the energized conductor 99.

The closing of the contact members a on the down-direction preference relay '72 completes a self-holding circuit for that relay which extends from the energized junction point 129, through conductor 234, contact members b of the down-,- direction relay 32, conductors 235 and 236, con tact members Ct of the direction-preference relay 72 and conductors 237 238, to the junction point 231 and thence, through the coil of the relay 72, conductors 233 and 113, the normally closed contact members 5 on relay 33, conductor 114, the normally closed contact members on relay 31 and conductor 115, to the energized conductor 99. v

The opening of the contact members on the preference relay 72 deenergizes the down control relay 34.

The openingof the contact members a on the down control relay 34 deenergizes the high-speed relay l-LS, thereby the resistor ZQ to be reconnected in series-circuit relation with the generator field winding 9. Consequently, the voltage developed by the generator AG will be reduced to thereby cause the hoisting motor M to decelerate to low speed.

down-direction preference relay '22 completes a circuit for energizing the inductor landing relay '79 so that it will be actuated'to stop the car point approximately on a level with the third floor, the energized inductor-landing relay 79 is brought adjacent to an inductor plate located in the hatchway at the third floor, which operates the landing relay 79 to open its normally closed contact members b, thereby deenergizing the down-direction relay Theopening of the contact bers a on the deenergized down-direction relay 32 deen gizes the down-direction switch 12 and the brakerelease relay 135. The deenergization of the switch 12 and the relay 133 causes the motor 4i to be disconnected from the generator and thebrake release coil 29 to be die-energised to permit the-brake 32 to be applied to the 33-, thereby bringing the car to a positive stop level I with the third fioor.

' time, resume its trip to the lower ter:

As previously described, upon the opening or" the down-direction switch 12, the ing field winding 19 is connected across the armature of the generator G to reduce the residual magnetism of the generator field poles to an proximately zero value in order to preent motor from pulling he car through the brake.

The opening of the contact members 2) on the deenergized down-direction relay 32 opens the self-holding circuit of the down preference relay 72 and deenergizes that relay so that car may restart after it has stopped.

The car A is now stopped level with the third floor and will remain there for a predetermined period of time to permit passengers in the corridor to open the door and gate and enter the car. If the passengers do not open the door and gate, the car will, at theend of the prede 'iinal.

Delay for a predetermined time is secured by adding a dash pot to the shaft upon which the contact members as, y and e of the 72 mounted. The dash pot causes the contact members 2 to open slowly and the contact members a: and y to close slowly in succession he relay 72 is deenergized.

The contact members 2 of the relay 72, when closed, complete one'gap in an auxiliary circuit for re-energizing the relay 72, the other gap of which may be closed the closure of the contact members g on the gate and door relay 36 when that relay is deenergiaed by someone opening the door or gate of the car. Therefore, because the contact members 2 of relay 72 are slow to open, they give the passenger an opportunity to re-energia the preference relay 72 within a predetermined time after the stops by opening the door or gate and thereby closing the second gap the circuit before the first gap is broken. When bother the gaps in the auxiliary circuit are closed, the preference relay 72 is re-energized, and the car will be held at the floor untilthe relay. 72 is again deenergized.

With tlie relay l2 ire-energized, the car cannot re-start because the control relay S i cannot be re-energized so long as the contact members a: on

the relay 72 are open. As noted before, the contact members a: are slow to close, and, therefore,

they keep the car from re-starting immediately after it stops. v

The contact members g on the preference relay 72 are electrically interlocked with the contact members r on the preference relay l1 for safety purposes and, therefore, should be set to close shortly after the contact members a: on relay 72 close.

While any suitable relay may be employed to perform the functions of the direction preference relays '71 and '72, I have schematically disclosed, in Fig. 11, a preference relay that will operate satisfactorily.

The direction preference relay shown in Fig. 11 is provided with contact members arranged like those on relays '71 and 72 comprising the normally open contact members a, e and z and the normally closed contact members 20, x and y.

The contact members a, e and w are secured to a bracket B that is pivotally mounted on a pin P. An armature AT is pivotally mounted on the bracket B and is disposed to be attracted towards a core C, upon which an actuating coil of th relayis mounted. Each pair of contact members :0, y and 2 comprises one movable and one stationary contact memben Each of the movable members associated with the stationarycontact members an and y is providedwith a spring 5 that is disposed to bias it towards a' closed circuit position. The movable member associated with the stationary member of the contact members e is provided with a spring 5 for biasing it towards an opencircuit position.

A plurality of cams C1, C2 and C3 are provided for actuating the contact members m, y and e. As shown, the cams are mounted on a shaft in such manner as to be displaced at an angle to each other. The relative angular displacement of the cams C1 and C2 is such that the contact members x will open before the contact members y and also close before the contact members 3!. The cam C3 is so arranged that the con act members a will be closed when the contact members x and y'are opened. I

When the coil of the relay is energized, the armature Ar will be attracted towards the core C, thereby closi g the contact members a and e instantly and opening the contact members winstantly. In order that the contact members 2;, y and 2 may be actuated in response to the energization of the coil C, the shaft Shis connected to the bracket B by a lever Z and a link m. As shown, one end of the lever'l is fixedly secured to the shaft Sh and its middle portion is mechanically connected to the lower tail piece 3' on the lower end of the bracket B by the link m. The

upper end of the link we loosely through a hole in the tail piece t and is provided with a head h that impinges against the upper side of the tail piece t so that the link will be moved upwardly when the bracket B is actuated by energiaation of the coil C. A spring :3 is secured to the free end of thelink m to bias the'shaft Sh to turn in a clockwise direction. A dash pot is mounted on the lower end of the link m to retard the downward movement of the link after it has been released by the bracket B and is being moved under the force exerted by the spring S Therefore, if the relay is energized, the inward movement of the bracket B will close the contact (rand e instantly and open the contact members to instantly. The inward movement of 

